1. Field of the Invention
The present invention generally relates to a cabled connector, and more particularly, to a balanced transmission connector with a balanced transmission cable which is used for connection between parts performing a balanced transmission of data, such as connection between a computer and a server.
A cabled connector is provided with a cable extending from a backside. A balanced transmission connector with a balanced transmission cable includes multiple terminals arranged suitably for a balanced transmission, in which the balanced transmission cable extends from a backside of the balanced transmission connector.
Methods of transmitting data between a computer and a server include a common transmission method using one wire for each data, and a balanced transmission method using a pair of wires for each data so as to transmit a +signal, which is originally to be transmitted, and simultaneously, a −signal reversed but equal in magnitude to the +signal. The balanced transmission method has an advantage of not easily influenced by noises in comparison with the common transmission method, and therefore is beginning to be employed for data transmission between a computer and a server.
As shown in FIG. 1, a server 1 has a structure in which a server body 2 is accommodated in a cabinet 3, and is installed on a free access  floor (a raised floor) 10. A space 5 appropriate for accommodating cables is prepared between a backside of the server body 2 and a door 4 at a backside of the cabinet 3. A plurality of cables 20 are drawn out from the free access floor 10, and connectors 21 at respective ends of the cables 20 are connected with respective connectors 6 at the backside of the server body 2. That is, the cables 20 leading out from the respective connectors 21 connected with the respective connectors 6 reach the free access floor 10 through the space 5. The door 4 at the backside of the cabinet 3 is closed so as to cover the cables 20. In this structure, a width S of the space 5 is designed to be as narrow as possible so that the server 1 has a small outside dimension.
Since a common cable has a moderate flexibility, each of the cables 20 curves moderately at a portion leading out from a backside of the connector 21 by a self-weight of the cable 20, and is adequately contained in the space 5, hardly causing a problem.
However, when the balanced transmission method is adopted, a number of wires increases approximately twice as many as a conventional number of wires. Accordingly, a balanced transmission cable 160 becomes hard, and cannot be expected to have a moderate flexibility. Therefore, the balanced transmission cable 160 is unable to curve moderately by a self-weight of the balanced transmission cable 160, and in a natural state, the balanced transmission cable 160 is unable to be contained in the space 5, but is likely to come out of the space 5, possibly causing a state in which the door 4 cannot be closed without an operator curving the balanced transmission cable 160 forcibly.
Thereupon, the balanced transmission cable 160 extending from the connector may be curved forcibly so as to extend further downward, as by the following means.
2. Description of the Related Art
FIG. 2 shows a conventional cabled connector 30 disclosed in Japanese Laid-Open Patent Application No. 1-100877. This connector 30 has a structure in which a cable-forcibly-curving means 31 is mounted beforehand on a connector cover 32. The cable-forcibly-curving means 31 forcibly curves a cable 40 leading backward from the connector 30. The cable-forcibly-curving means 31 has a structure capable of curving the cable 40 at various angles so that the cable 40 can be drawn out selectively in various directions.
In the structure of the cable-forcibly-curving means 31, ball pairs 34 for hooking the curved cable 40 are arranged at a plurality of positions along a circular-arc cover 33, making the structure considerably large in size.
Besides, when a transmission rate of data is as high as 1 Gbit per second, a signal wavelength becomes short so that an electromagnetic wave generated in the connector becomes likely to leak out of the connector. Therefore, measures need to be taken against electromagnetic interference (EMI) for the connector. However, EMI measures are not sufficiently taken for the structure of the connector 30.